cup of tea vs tea plant

cup of tea

noun
  • Used other than figuratively or idiomatically: see cup, tea. A cup or mug with tea in it. 

  • three 

  • Whatever suits or interests one. 

tea plant

noun
  • The bush Camellia sinensis, the leaves of which are picked, dried and used to make the beverage tea. 

How often have the words cup of tea and tea plant occurred in a corpus of books? (source: Google Ngram Viewer )